Dear Nick,

Being on vacation with a girlfriend is fine. It's the sharing of the same room that's the problem.

You're correct that sex before marriage (as well as lust and sexual stimulation) is directly sinful. However, it is also a moral imperative to never be the cause of scandal to others and to avoid the near-occasion of sin.

Sleeping in the same room at night, even if there are different beds, is rather intimate. It's morally dangerous for people, mutually attracted to each other, to share a bedroom. It's best to avoid this before marriage, for one's own sake and the sake of others who see two unmarried Catholics sharing a bedroom.

Peace,

Paul